I have a Hill MK4 pump with absorber kit. It was not working well and I have been using a scuba tank for a couple years. I ordered a rebuild kit and repaired the pump and it works great. Dri pak was replaced June 26 and the pump has only been used to test. It pumped my pistol up to 3k in about 3 min pumping slowly. Includes an extra dri pak, some silicone lube, and spare o rings. $140 shipped to Conus. Paypal or venmo seems easiest
Here is the rebuild kit I used. https://www.airgunsofarizona.com/factory-parts/hill-mk4-full-service-seal-kit/
Here is the rebuild kit I used. https://www.airgunsofarizona.com/factory-parts/hill-mk4-full-service-seal-kit/